Re: [Qemu-devel] [PATCH v3 07/20] kvm: arm/arm64: Prepare for VM specific stage2 translations

[Suzuki K Poulose]

Hi Eric,

On 02/07/18 11:51, Auger Eric wrote:
> Hi Suzuki,
>
> On 06/29/2018 01:15 PM, Suzuki K Poulose wrote:
> > Right now the stage2 page table for a VM is hard coded, assuming
> > an IPA of 40bits. As we are about to add support for per VM IPA,
> > prepare the stage2 page table helpers to accept the kvm instance
> > to make the right decision for the VM. No functional changes.
> > Adds stage2_pgd_size(kvm) to replace S2_PGD_SIZE. Also, moves
> > some of the definitions dependent on kvm instance to asm/kvm_mmu.h
> > for arm32. In that process drop the _AC() specifier constants
> >
> > Cc: Marc Zyngier <address@hidden>
> > Cc: Christoffer Dall <address@hidden>
> > Signed-off-by: Suzuki K Poulose <address@hidden>
> > ---
> > Changes since V2:
> >   - Update commit description abuot the movement to asm/kvm_mmu.h
> >     for arm32
> >   - Drop _AC() specifiers


> > diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h
> > index 8553d68..f36eb20 100644
> > --- a/arch/arm/include/asm/kvm_mmu.h
> > +++ b/arch/arm/include/asm/kvm_mmu.h
> > @@ -36,15 +36,19 @@
> >         })
> >   
> >   /*
> > - * KVM_MMU_CACHE_MIN_PAGES is the number of stage2 page table translation 
> > levels.
> > + * kvm_mmu_cache_min_pages() is the number of stage2 page
> > + * table translation levels, excluding the top level, for
> > + * the given VM. Since we have a 3 level page-table, this
> > + * is fixed.
> >    */
> > -#define KVM_MMU_CACHE_MIN_PAGES        2
> > +#define kvm_mmu_cache_min_pages(kvm)   2
> nit: In addition to Marc'c comment, I can see it defined in
> stage2_pgtable.h on arm64 side. Can't we align?

Sure, will do that.

> > diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h
> > index fb9a712..5da8f52 100644
> > --- a/arch/arm64/include/asm/kvm_mmu.h
> > +++ b/arch/arm64/include/asm/kvm_mmu.h
> > @@ -141,8 +141,11 @@ static inline unsigned long __kern_hyp_va(unsigned long v)
> >    * We currently only support a 40bit IPA.
> >    */
> >   #define KVM_PHYS_SHIFT        (40)
> > -#define KVM_PHYS_SIZE  (1UL << KVM_PHYS_SHIFT)
> > -#define KVM_PHYS_MASK  (KVM_PHYS_SIZE - 1UL)
> > +
> > +#define kvm_phys_shift(kvm)            KVM_PHYS_SHIFT
> > +#define kvm_phys_size(kvm)             (_AC(1, ULL) << kvm_phys_shift(kvm))
> Can't you get rid of _AC() also in arm64 case?

> > +#define kvm_phys_mask(kvm)             (kvm_phys_size(kvm) - _AC(1, ULL))

Yes, that missed. I will do it. Thanks for spotting.

Cheers
Suzuki